Disa longicornu

Assessor: Sarah Schumann

Sensitive in 2010
Yes
Family
Orchidaceae
Reason for the sensitivity status
This species is known to be experiencing population decline due to over-collecting and picking of its flowers at all locations. Few known locations of occurrence with threat of over-collection places the persistence of this species at risk whereby recruitment and recovery may be poor. Releasing data on this species could exacerbate threat and vulnerability.
This species is extremely rare in the wild and is known to be exploited, utilised or traded. The localities of remaining populations need to be protected to avoid any further exploitation, which is likely to drive it to extinction.
Exploitation extent
Significant - wild individuals of the species are known to be exploited, collected, traded or utilized in a targeted manner, and utilisation is widespread, affects the majority of wild populations and/or is causing rapid decline of the wild population.
Justification and references

According to the SANBI Red List Assessment, this species is Vulnerable as it known from few locations that are experiencing population decline due to over-collecting and picking of its flowers at all locations (von Staden et al. 2012). Other species in this genus are known to be threatened by collection of wild individuals (von Staden & Liltved, 2012).

von Staden, L., Oliver, E.G.H. & Raimondo, D. 2012. Disa longicornu L.f. National Assessment: Red List of South African Plants version 2020.1.

von Staden, L. & Liltved, W.R. 2012. Disa lugens Bolus var. nigrescens (H.P.Linder) H.P.Linder. National Assessment: Red List of South African Plants version 2020.1. 

Population vulnerability
Population is vulnerable: size is <= 2500 mature individuals OR the number of known subpopulations is <= 5 OR range is <= 100km2 OR species at risk of localised extinctions
Justification and references

This taxon has an extent of occurrence of  294 kmĀ² and is known from six locations with a declining population trend (von Staden et al. 2012).

von Staden, L., Oliver, E.G.H. & Raimondo, D. 2012. Disa longicornu L.f. National Assessment: Red List of South African Plants version 2020.1.

Targeted demographics
Mature (breeding) individuals are killed, significantly weakened or are permanently removed from the wild, OR immature individuals are targeted and this significantly impacts mature (breeding) individuals.
Regeneration potential
This species has a slow population growth rate, or the growth rate varies depending on habitat, and there is a poor chance the wild populations will recover from exploitation OR a collector might feasibly harvest the entire extant population removing the chance of subsequent recruitment.
Justification and references

Few known locations of occurrence with threat of over-collection (von Staden et al. 2012), places the persistence of this species at risk whereby recruitment and recovery may be poor.

von Staden, L., Oliver, E.G.H. & Raimondo, D. 2012. Disa longicornu L.f. National Assessment: Red List of South African Plants version 2020.1.